I am a work in progress!
myAnswer: For one, I don't wear this every workout, only when I workout at home so 50% of the time its core activation and with that [habit] it makes it more innate for me to keep my core engaged with all exercise. Personally, I like the pressure as a little reminder to keep things extra tight. I love the support it gives my back when I go heavy on weights and off course I love seeing how flat my belly is when I'm done and all the water that comes pouring out while I use it and when I take them off. May not be for everyone, but As I said, in the video, I've been using these for YEARS! I remember when there was A LOT more to wrap when I was over 200lbs.
yourQuestion: Is there a reason you use two?
myAnswer: I use two because I have a long torso and I want EVERYTHING covered from boob crease to my hip - upper & lower abs. If I used one, I'd have to choose which area I wanted the coverage. Also, IF someone is overweight with a large midsection (which I used to have), one just doesn't provide the coverage. It will curl and not keep everything under wraps. I know!